1. Field of the Invention
The present invention relates to a video recording and reproducing apparatus and a control method of the video recording and reproducing apparatus. More particularly, the present invention relates to a video recording and reproducing apparatus configured to temporarily record video content data in a storage unit and to perform upconverting to provide high-quality image and sound in playback of the recorded video content data and a control method of the video recording and reproducing apparatus.
2. Description of the Related Art
In recent years, server-type broadcasting systems have come into practical use. In a server-type broadcasting system, a video recording and reproducing apparatus stores and utilizes video content data that is transmitted from a server apparatus via a digital broadcast wave or a broadband network.
In the server-type broadcasting systems, viewers can view a desired program content by obtaining a license from a content provider.
Similarly, video on demand (VOD) services by which a viewer can watch content such as a movie at any desired time has come into common use. In a VOD service, similar to the server-type broadcasting system, license-managed video content data is delivered from a content provider to a Set Top Box (STB) for the VOD service use. The viewer can watch the video content data delivered to the STB by displaying the data on a display device such as a television (TV). Until recently, in a conventional VOD service, the viewer could not store the video content data in a storage device such as a hard disk drive (HDD). However, recently, there are VOD services in which the STB includes a hard disk drive (HDD) so that license-managed video content data can be temporarily stored.
Generally, a viewing deadline is set to the license-managed contents, so that a viewer cannot watch the contents after the designated viewing deadline passes.
However, for example, Japanese Patent Application Laid-Open No. 2006-33231 discusses a method that can prevent a case where the viewing deadline expires while the viewer is still watching the content so that the viewer can no longer continue watching the content. In the control method discussed in Japanese Patent Application Laid-Open No. 2006-33231, it is detected whether remaining time up to a viewing deadline of moving image content is shorter than time necessary for playing back the moving image content. If the remaining time is shorter than the time necessary for playback of the moving image content, a playback speed which enables the viewer to watch the content to the end is calculated and multispeed playback can be performed.
Until recently, a maximum number of effective pixels of video broadcasted in a digital broadcasting service is a high definition (HD) format of 1920×1080. However, with a recent significant advance in display panel technology, resolutions of display devices have improved to a Super High Definition (SHD) format of 4000×2000.
A technology in which content in standard definition (SD) format or the HD format received from a broadcast service or a VOD service are converted into higher quality resolutions and sounds (hereinafter, referred to as upconvert) by a high-performance computing device have also recently been developed. For example, Japanese Patent Application Laid-Open No. 2004-246526 discusses an upconverting technology in which each pixel in video is analyzed whether any regular lines of contrast difference exist between the pixel and surrounding pixels. Based on the regularity, a numerical expression representing an image in a real world that has caused the contrast difference can be estimated. Based on the numerical expression, a high-resolution image can be obtained. However, the above described upconverting technology includes a very complicated algorithm which is computationally intensive.
Generally, the above described upconverting technology utilizing the complicated algorithm can assure a higher image quality as compared with simple resolution conversion. However, the upconverting requires a longer processing time period than the actual time that the video content takes to be displayed. Accordingly, it is difficult to perform playing back of stored video and a high-quality image processing at the same time.
Concerning the above-described technologies, systems have been proposed that can automatically upconvert video content at the SD or HD level stored in a storage device into video data of the SHD level.
In such system, it is important to provide upconverted video contents as much as possible at a timing when a viewer desires to watch a high image quality video content. Accordingly, generally, all stored video contents are upconverted.
However, when video content having a viewing deadline stored in a video recording and reproducing apparatus, that corresponds to the above-described server type broadcasting systems or the VOD services, is upconverted (even if a high-performance computing processing device is used), the following problems may occur.
As described above, viewing deadlines are usually set to video contents which can be watched in the above-described services. Accordingly, when the upconverting is performed on the video content that takes long time, the viewing deadlines can expire before the upconverting is completed. Moreover, even if the upconverting is completed by the viewing deadlines, after the completion of the upconverting process, there may not be enough time remaining before the deadline to watch the upconverted content. Thus, the execution of the upconverting process itself can be a problem.
Moreover, if the upconverting process is performed on video content that does not require the upconverting process, a problem may arise that an insufficient processing time period is provided for other video content that needs to be upconverted.